Electrical connectors for optoelectronic device packaging

ABSTRACT

Packaged optoelectronic device include a first barrier layer having a plurality of feedthrough apertures communicating with at least one electrode layer of the device, and a plurality of conductive patches disposed on at least one of the plurality of feedthrough apertures for electrically connecting the device to a power supply. Each conductive patch includes a conductive metal surface layer and a non-conducting surface layer having an opening exposing the metal surface layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of copending U.S. applicationSer. No. 12/470,033, filed 21 May 2009, the entire contents of which isincorporated herein by reference.

BACKGROUND

Optoelectronic devices generally include light-emitting devices andphotovoltaic devices. These devices generally include an active layersandwiched between two electrodes, sometimes referred to as the frontand back electrodes, at least one of which is typically transparent. Theactive layer typically includes one or more semiconductor materials. Ina light-emitting device, e.g., an organic light-emitting diode (OLED), avoltage applied between the two electrodes causes a current to flowthrough the active layer. The current causes the active layer to emitlight. In a photovoltaic device, e.g., a solar cell, the active layerabsorbs energy from light and converts this energy to electrical energyexhibited as a voltage and/or current between the two electrodes.Optoelectronic devices may be produced by various means. One approach isto use vacuum deposition of semiconductor materials, and a secondapproach is to use solution processed materials. Various substratesincluding glass and plastic film can be used as a base for depositingthe layers on. Alternately, the optoelectronic device may be built usingthe opaque layer (metal or polymer or ceramic) as the substrate and analternate build sequence is employed. Regardless of the construction ofthe device, it is necessary to provide an encapsulating hermetic packageto protect it from the deteriorating effects of moisture and oxygenexposure. The package must also provide electrical interconnections in afeedthrough configuration to connect a power supply that is external tothe package.

OLEDs are produced in a flat thin format for use as displays or forgeneral illumination. The use of a plastic substrate provides thethinnest and most flexible configuration, and also the potential for lowcost roll-to-roll production. Accordingly, there is a need for packagingtechnology that is also thin and flexible, and preferably amenable toroll-to-roll production coincident with the OLED fabrication. Thepackage should be suitable for large area (up to about one or moresquare meters) displays or luminaries for particular applications.

Barrier films, referred to as ultra high barrier (UHB) films or UHBs,are used for direct fabrication of OLEDs and other optoelectronicdevices. These films typically consist of a thin transparent oxide layeron a transparent plastic film, for example, as described in U.S. Pat.No. 7,015,640, U.S. Pat. No. 7,154,220, and U.S. Pat. No. 7,397,183assigned to the General Electric Company. However, the barrier films canbe damaged in handling, so that fabricating a device directly on thebarrier film may degrade its performance and create a moisture ingresspath. In addition, moisture and oxygen can permeate laterally throughadhesive layers at the edges of the device and also through the adhesivethat seals the electrical wire feedthroughs. Moreover, intrinsicmoisture in the adhesive and substrate materials can damage the device.The package design must be compatible with low cost materials andcontinuous roll-to-roll production, and the material set must be lowcost and suitable for high speed processing. Thus, there is a need foran improved thin flexible packaging technology for expanded applicationof low cost production of OLEDs and other optoelectronic devices. U.S.application Ser. No. 12/470,033, filed 21 May 2009 describes methods forpackaging optoelectronic devices utilizing a piece or sheet ofconductive material covering feedthrough apertures in a barrier layer tocouple electrodes of an optoelectronic device to electricalinterconnectors, and ultimately to a power supply. However, improvedmethods and materials for manufacturing the patch and coupling the patchto the electrodes are desirable.

BRIEF DESCRIPTION

Briefly, in one aspect, the present invention relates to processes forpackaging an optoelectronic device. The process includes providing apartially packaged optoelectronic device comprising a first barrierlayer having a plurality of feedthrough apertures exposing at least oneelectrode layer of the device; providing a plurality of conductivepatches, each conductive patch comprising a conductive metal surfacelayer and a non-conducting surface layer having an opening exposing theconductive layer; applying a conductive patch to each of the feedthroughapertures; and making contact between the conductive metal surface layerof each conductive patch and one of the at least one electrode layers ofthe device. In the context of the present invention, the term “patch”refers to a piece or sheet of conductive material used to cover thefeedthrough apertures.

In another aspect, the present invention relates to a packagedoptoelectronic device including a first barrier layer having a pluralityof feedthrough apertures communicating with at least one electrode layerof the device, and a plurality of conductive patches disposed on atleast one of the plurality of feedthrough apertures; wherein eachconductive patch comprises a conductive metal surface layer and anon-conducting surface layer having an opening.

DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a perspective view of a packaged optoelectronic deviceaccording to the present invention.

FIGS. 2A and 2B are partial cross-sectional views of a packagedoptoelectronic device showing details of patch construction.

FIG. 3 is a cross-section view of a packaged optoelectronic devicehaving a contoured conductive patches.

FIGS. 4A-4C are partial cross-sectional views of a packagedoptoelectronic device showing patches is various locations.

FIGS. 5A-5E is a schematic diagram of a process for fabricating apackaged optoelectronic device according to the present invention.

FIG. 6 shows an apparatus for fabricating patches for use in packagedoptoelectronic device according to the present invention.

FIGS. 7A and 7B are illustrations of artwork for use in singulatingpatches for packaged optoelectronic device according to the presentinvention.

DETAILED DESCRIPTION

FIG. 1 is a perspective schematic view of a packaged optoelectronicdevice according to the present invention. Device 100 composed ofsubstrate 102, continuous, unpatterned anode 112, electroactive layers122, cathode areas 132, (optional) anode buses 136, and feedthroughlayer or backsheet 142, containing feedthrough apertures 162. Anodeconductive patches 152 cover feedthrough apertures (not shown) that areconfigured to allow electrical connection between the patches and anodelayer 112 through anode buses 136; an external power source may beconnected through the patches to power the device. Where the anode busesare absent, the patches may be directly coupled to the anode. Similarly,cathode conductive patches 154 are electrically coupled to cathode areas132 through feedthrough apertures (not shown). The conductive patchesare composed of a conductive metal surface layer and are electricallyinsulated from backsheet 142 by a non-conducting surface layer (notshown). The non-conducting layer includes an opening through which theconductive metal layer is electrically coupled to the cathode or anode.

Substrate 102 may be composed of a transparent flexible material, suchas flexible glass and transparent flexible plastics, such as polyestersand polycarbonates, particularly optical grades of such plastics.Substrate 102 may additionally include a transparent barrier layer, ormultiple barrier layers. Materials suitable for use as barrier layersinclude, but are not limited to those having a moisture permeabilityrate less than approximately 10⁻⁴ cc/m²/day, preferably less than 10⁻⁵cc/m²/day, and more preferably less than approximately 10⁻⁶ cc/m²/day(at 23° C.), particularly UHB materials, such as described in U.S. Pat.No. 7,015,640, U.S. Pat. No. 6,413,645, U.S. Pat. No. 6,492,026, U.S.Pat. No. 6,537,688, and U.S. Pat. No. 6,624,568, flexible or rigidglass, transparent metals and oxides having sufficient moisture and/oroxygen barrier properties, such as ITO, and combinations of these. Insome embodiments, UHB materials or glass may be used, and in particularembodiments, UHB materials are used.

Materials for use as anode 112 are well known in the art, and will notbe discussed in detail. In particular embodiments, the anode may becomposed of indium tin oxide (ITO), especially where the optoelectronicdevice is an OLED. Materials, configurations of those materials, andprocesses for fabricating OLED devices, are described in U.S. Pat. No.6,661,029, U.S. Pat. No. 6,700,322, U.S. Pat. No. 6,800,999 and U.S.Pat. No. 6,777,871, assigned to General Electric Company, the contentsof which are incorporated by reference. Electroactive layers 122 may becomposed of various layers of materials as described in the referencedpatents.

Cathode areas 132 and anode bus 136 are typically composed of a materialhaving a low work function value such as aluminum. In some embodiments,besides the aluminum, calcium or a metal such as silver, magnesium, or amagnesium/silver alloy. Alternatively, the cathode may be made of twolayers to enhance electron injection. Non-limiting examples of thecathode may comprise a thin inner layer of LiF followed by a thickerouter layer of aluminum, or a thin inner layer of calcium followed by athicker outer layer of aluminum or silver.

Backsheet 142 may be any impermeable thin film, including metal foils,or polymer films such as Honeywell ACLAR® polychlorotrifluoroethylene(PCTFE). Multilayer foils that include a thin interface layer, a barrierlayer, and an optional insulating or non-conducting layer, may also beused, particularly commercially available multilayer packaging orlidding materials having moisture- and optionally oxygen-barrierproperties in the form of films or sheets, especially heat-sealablematerials. Lidding materials are typically composed of multiple thinpolymer layers; lidding foils also include a metal foil, typicallyaluminum, sandwiched between polymer layers. One example of a suitablematerial for backsheet 201 is Tolas TPC-0814B lidding foil, produced byTolas Healthcare Packaging, Feasterville, Pa., a division ofOliver-Tolas, Grand Rapids, Mich. Feedthrough apertures 162 are formedin backsheet 142 using any suitable methods, including punching, diecutting, and laser machining. The apertures may be round, of varieddiameter, or of other shapes and aspect ratios depending on the layoutof the device and other design factors.

FIGS. 2A and 2B show details of patch construction and integration withbacksheet 242 and electrode 232, either an anode or a cathode, of apackaged optoelectronic device according to the present invention,illustrating structures for electrically coupling the patch to thedevice. Patch 201 is composed of conductive layer 203, optionalnon-conducting layer 205 and adhesive layer 207. It is substantiallylarger than feedthrough aperture 211 and may be sealed to backsheet 242by adhesive layer 207. Suitable materials for conductive layer 203include sheets or foils of conductive metal, such as aluminum, stainlesssteel, or copper, that are of sufficient thickness and homogeneity to beimpermeable to moisture, oxygen, and/or other vapors that may have adeleterious effect on the device. Non-conducting layer 205 preventsphysical and electrical contact between conductive layers of patch 201and backsheet 242, and is composed of a non-conductive polymer materialthat does not melt or flow at fabrication temperatures, typicallygreater than about 100° C. One example of a suitable material ispolyimide. A copper foil-polyimide laminate may be used for conductivelayer 203 and non-conducting layer 205; one material that may be used isPYRALUX® AC 182000R, commercially available from DuPont. Adhesive layer207 may be composed of a thermoplastic or thermoset material. Selectioncriteria for the adhesive include whether it is a single or dualcomponent system, shelf life, processing/application/solvents, opticalcoupling, cure temperature (if any), electrode (cathode) compatibility,adhesion, and moisture resistance. Examples of suitable thermoplasticsinclude EVA (ethylene vinyl acetate copolymers), ADCOTE® heat sealableethylene copolymers available from Rohm & Haas Company, PRIMACOR®ethylene acrylic acid copolymers available from Dow, and pressuresensitive adhesives, such as 3M film 200 MP (2 to 5 mil) or FlexconFlexmark V-95 acrylic adhesives. Examples of suitable thermosettingadhesives that typically require frozen or two-component blends, includeepoxies, such as those available from 3-Bond and Robnor, urethanes (twocomponent), available from Mitsui Tekenate and 3M, and two-componentacrylic systems, available from Loctite/Henkel, Lord, and 3M. Systemsthat require additional handling such as the frozen and two-componentblends are less desirable, but may be used if desired.

Patch 201 is electrically coupled to electrode 232 by conductive element231 (FIG. 2A) or conductive element 241 (FIG. 2B). either of which areconveniently formed from an electrically conductive adhesive applied infeedthrough aperture 211. FIG. 2A illustrates use of a conductor-filledadhesive paste, for example, a conductive silver filled epoxy adhesivepaste, such as Staystik 571, available from Cookson Electronics,Alpharetta, Ga. Contact between a backsheet composed of a metal andconductive element 231 may result in electrical shorting and may beprevented by controlling the amount of paste applied to feedthroughaperture 211. In FIG. 2B, conductive element 241, in the form of a filmmay be composed of an isotropic or anisotropic electrically conductivetape, consisting of a conductive acrylic pressure sensitive adhesiveloaded with conductive particles. Anisotropic conductive films allowinterconnection through the adhesive thickness, that is, in theZ-direction, but are electrically insulating in the plane of theadhesive, the X- and Y-directions. Isotropic conductive films may beconductive in all of the X-, Y-, and Z-directions. Examples of suitableconductive film materials include 3M 9703, 3M 9709SL and AdhesiveResearch ARcare8881.

FIG. 3 shows an alternate embodiment of an optoelectronic deviceaccording to the present invention device 300, in which the surfaceprofile on both sides of patch 301 is contoured. Patch 301 is composedof conductive layer 303, optional insulating layer (not shown), andnon-conductive adhesive layer 307 and has a bowl-shaped or dimple-shapedindentation at its center. The insulating layer and adhesive layer 307have been removed in the area opposite the indentation, exposingconductive layer 303 on both sides. The depth of the indentation on thepatch before installation is d₁. The cross sectional area at anylocation of the patch remains constant across the area of the patch. Thedepth d₁ is equal or larger than the step height d₂. Step height d₂ isthe step from the contacts to the isolating layer of the backsheet inthe feedthrough aperture. When the patch is installed on insulatinglayer of the backsheet via the adhesive layer, d₁ will become equal tod₂ because of plastic and elastic deformations that take place of themost compliant material layers during the patch installation process.The patch can be installed using roll lamination or vacuum lamination.The forces, moments and pressures in the feedthrough after installingthe patch to the backsheet are the result of plastic and elasticdeformations of the material system that occur when the indentationdepth d₁ is greater than step height d₂. Force F is the adhesion forcefrom the adhesive layer bonding the patch to the backsheet. Force F actson the patch in an annular perimeter zone around the perimeter. Force Falso acts with equal magnitude but opposite direction on the annularzone around the feedthrough hole in the backsheet, and results in apressure field p in the center of the patch. The pressure zone iscreated at the electrical interfaces between the patch, the conductiveadhesive and the anode and cathode contacts. The pressure field pdecreases the contact resistance between the patch, conductive adhesiveand the electrode contacts (anode and cathode).

Transparent layers of device 300 include combination substrate andbarrier layer 302, optional adhesion promotion layer (not shown) andoptional optical outcoupling layer (not shown) and electrode (anode)312. Electroactive layers 322 and 332 are disposed on anode 312. Theother side of package 300 consists of multi-layer backsheet 342 thatcontains adhesive layer (not shown) and optional non-conducting layer(not shown). The adhesive layer on multi-layer backsheet 342 and theoptional adhesion promotion layer form a seal zone with combinationsubstrate and barrier layer 302 at the perimeter of package 300.Adhesive layers 307 form seal zones with multi-layer backsheet 342around the feedthrough aperture 311. Electrical connection to anode bus336 and cathode 332 is made through feedthrough aperture 311 inbacksheet 342 through conductive adhesive 331.

FIGS. 4A-4C show schematically embodiments of the present inventionwherein conductive patches 401 and feedthrough apertures 411 aredisposed in different locations within a package. In FIG. 4A, patch 401is located between backsheet 442, composed of conductive metal surfacelayer 443 and insulating layer 445, and electrode 431 and electrode 433.In FIG. 4B, backsheet 442, with conductive metal surface layer 443 andinsulating layer 445, is located between electrode 431 or electrode 433and patch 401. In FIG. 4C, patch 401 is located between first backsheetbarrier layer 442, which functions as a barrier layer, and is made up ofconductive metal surface layer 443 and insulating layer 445, and secondbacksheet 447, also functioning as a barrier layer, and made up ofconductive metal surface layer 448 and insulating layer 449.

The present invention also relates to processes for packaging anoptoelectronic device. The processes include

-   -   providing a partially packaged optoelectronic device comprising        a first barrier layer having a plurality of feedthrough        apertures exposing at least one electrode layer of the device;    -   providing a plurality of conductive patches, each conductive        patch comprising a conductive metal surface layer and a        non-conducting surface layer having an opening exposing the        conductive layer;    -   applying a conductive patch to each of the feedthrough        apertures; and    -   making contact between the conductive metal surface layer of        each conductive patch and one of the at least one electrode        layers of the device.

The step of providing a plurality of conductive patches may includeremoving a portion of the at least one non-conducting layer to form avia and exposing the conductive metal through the via.

EXAMPLES

The following examples illustrate a process according to the presentinvention.

Example 1

FIG. 5 is a flowchart graphically illustrating steps for fabricating apatch. FIG. 5A shows the starting material, single sided copper cladlaminate 560. Pyralux AC-182000R, available from DuPont, which is 18micron thick copper foil 563 attached to 20 micron thick polyimidedielectric 561, was used.

Fabrication of Patch Using Copper Clad Material

A sheet of the copper clad material 661 is attached to a frame orpressed into snap rings 670, 671, and 672 as shown in FIG. 6. The filmis cleaned, the dielectric side is optionally plasma treated to improveadhesion to its surface. In the next step, illustrated in FIG. 5B,polyimide dielectric 561 is then coated with adhesive 565. The adhesivelayer 565 is Adcote 37T77, available from Rohm and Hass, which isapplied by spin coating. Other possible methods include spray coating orslot die coating. The solvent in the adhesive is removed by baking,leaving a thermoplastic coating which is tack-free at room temperature.In FIG. 5C, release film 567 is applied to the surface of this adhesiveto protect it during subsequent processing steps. The next step, shownin FIG. 5D is to selectively remove part of polyimide dielectric 561,adhesive 565, and release film 567 from the center of the patch toexpose the conductive copper material 563. In this embodiment, a 12micron thick Kapton polyimide layer is placed over the top of the Adcoteadhesive 565 and lightly laminated to the surface at 115° F. using avacuum-pressure lamination process. This process lasts about one minuteunder vacuum followed by one minute under pressure using an OPTEK DPL-24Differential Pressure Laminator. The Kapton acts as a release film thatis only lightly attached to the adhesive under these processingconditions. Patterned sections of the release layer, adhesive andpolyimide clad are then removed to expose the metal foil. This is mosteasily accomplished using direct write, laser ablation tool, such as anESI-5200 UV laser. Using a square-spiral tool path, large areas of thecoatings can be removed to expose the metal foil with minimal soot.Using step and repeat, single or multiple contact areas in each patchare made as well as placement of alignment points for subsequentsingulation of the patches are made using a single artwork. Followinglaser ablation, the sample is processed through a reactive ion etchprocess to remove any remaining soot on the metal surface to ensure goodelectrical contact. Release layer 567 is then removed as shown in FIG.5E, leaving behind polyimide dielectric 561, adhesive 565, conductivecopper material 563, and patches singulated for use. FIGS. 7A and 7Bshow artwork for use in singulating. FIG. 7A shows rows of openings 710and crosses 713 indicating corners of each patch. FIG. 7B shows artworkfor patches containing two openings 720 each; dots 722 indicate cornersof the patches.

The electrical connection between the copper of the patch and theevaporated aluminum that form the anode contact and cathode contact ismade with Tra-Duct 2902 conductive silver filled epoxy that is cured for30 to 60 minutes at a temperature of 70 degrees Celsius. After curingthe epoxy the patch is laminated to the backsheet at 140 degrees F.

Example 2

The conductive adhesive layer is an electrically conductive tape withsilver particles and pressure sensitive adhesive such as 9707SLavailable from 3M Company. This tape is electrically conductive in thex-, y- and z-directions. Other suitable materials are pressure sensitiveadhesive tapes that are electrically conductive in only the normaldirection (z-direction) such as 3M 9703 or 9705. The conductive tape isput down on the contacts on the OLED before the backsheet is put down.Another possibility is to put down the tape on the patch. The backsheetis TOLAS 0814B with 5 mm diameter feedthrough aperture holes. The stepheight is 100-125 micrometers at the holes. Square patch of 20 mm by 20mm is cut out from Pyralux AC-182000R copper clad material availablefrom DuPont. The adhesive region and insulating dielectric region areproduced as described in Example 1. The adhesive is ADCOTE® 37T77,supplied by Rohm & Haas Company, but could also be a pressure sensitiveadhesive (PSA) or similar adhesive that is favorable for roll-to-rollproduction.

A circular indentation with a depth d₁ of 200 μm to 300 μm is formed inthe center of the patch where the conductive copper is exposed. Theindentation is formed by plastically deforming the copper metal layerwith a steel punch and soft backing surface. Other methods to make theindentation include knurling, stamping and laser forming. The differencein indentation depth d₁ and step height d₂ at the holes of 100 μm to 125μm and the compliance of the stacked adhesive layers and optionalinsulative layer determine the magnitude of the pressure field p1 at theelectrical contact zone and the normal forces F at the perimeters of thefeedthrough aperture hole and patch. The normal forces preload theelectrical contact area and decrease contact resistance.

It is also possible to change the patch by altering its cross sectionalarea. The cross sectional area of the patch can be increased in selectareas, for example by means of electrolytic plating or adding solderpaste or silver epoxy. The cross sectional area of the patch can also bedecreased in select areas, for example by chemical etching processes orlaser ablation. The cross section of the patch 160 should be altered sothat it is thicker in the center and thinner at the perimeter. Duringroll or vacuum lamination of the patch 160 to the backsheet thecontoured patch design will see increased pressure at its center. Whengoing through a roll or vacuum lamination step more pressure is exertedon the electrical contact zone compared to a patch that is contouredwith a constant thickness or cross section geometry.

While only certain features of the invention have been illustrated anddescribed herein, many modifications and changes will occur to thoseskilled in the art. It is, therefore, to be understood that the appendedclaims are intended to cover all such modifications and changes as fallwithin the true spirit of the invention.

The invention claimed is:
 1. A roll to roll process for packaging anoptoelectronic device, said process comprising providing a partiallypackaged optoelectronic device in roll format, said partially packagedoptoelectronic device comprising a substrate, a plurality ofelectroactive layers sandwiched between a cathode and an anode, and afirst barrier layer having a plurality of feedthrough apertures exposingthe cathode and the anode; providing a plurality of conductive patches,each conductive patch comprising a conductive metal surface layer and anon-conducting surface layer having an opening exposing the conductivelayer; applying a conductive patch to each of the feedthrough apertures;and making contact between the conductive metal surface layer of eachconductive patch and at least one of the cathode and the anode.
 2. Aprocess according to claim 1, wherein providing a plurality ofconductive patches comprises removing a portion of the at least onenon-conducting layer to form a via and exposing the conductive metalthrough the via.
 3. A process according to claim 2, additionallycomprising forming an indentation in the conductive metal surface.
 4. Aprocess according to claim 3, additionally comprising removing a portionof the at least one non-conducting layer in an area opposite theindentation.
 5. A process according to claim 1, additionally comprisingdisposing a conductive adhesive material within each of the plurality offeedthrough apertures.
 6. A process according to claim 5, wherein makingcontact between the conductive metal surface layer of each conductivepatch and one of the at least one electrode layers of the devicecomprises making contact through the conductive adhesive material.
 7. Aprocess according to claim 5, wherein the conductive adhesive materialis derived from a conductive thermosetting adhesive.
 8. A processaccording to claim 5, wherein the conductive adhesive material is ananisotropic conductive film.
 9. A process according to claim 5, whereinthe conductive adhesive material is an isotropic conductive film.
 10. Aprocess according to claim 5, wherein the conductive adhesive materialis a conductive silver filled epoxy.
 11. A process according to claim 1,additionally comprising sandwiching the conductive patches between thefirst barrier layer and a second barrier layer having a plurality offeedthrough apertures, wherein each conductive patch is exposed throughat least one of the plurality of feedthrough apertures.
 12. A processaccording to claim 2, wherein removing a portion of the at least onenon-conducting layer to form a via and exposing the conductive metalthrough the via comprises mounting to a support a metal-clad laminatecomprising a conductive metal surface and at least one non-conductinglayer; coating the at least one non-conducting layer with an adhesivelayer; applying a release coating to the adhesive layer; and ablating aportion of each of the non-conducting layers to expose the conductivemetal surface.
 13. A process according to claim 2, wherein applying aconductive patch to each of the feedthrough apertures comprises removingthe release film from the non-conducting surface and disposing theconductive patch on at least one of the feedthrough apertures.
 14. Apackaged optoelectronic device in roll format, the packagedoptoelectronic device comprising a substrate, a plurality ofelectroactive layers sandwiched between a cathode and an anode and afirst barrier layer having a plurality of feedthrough apertures exposingat least the cathode or the anode of the device, and a plurality ofconductive patches disposed on at least one of the plurality offeedthrough apertures; wherein each conductive patch comprises aconductive metal surface layer and a non-conducting surface layer havingan opening.
 15. A packaged optoelectronic device according to claim 14,wherein a conductive adhesive material is disposed within each of theplurality of feedthrough apertures and contacts the conductive metalsurface layer and one of the at least one electrode layers.
 16. Apackaged optoelectronic device according to claim 14, wherein theconductive adhesive material is derived from a conductive thermosettingadhesive.
 17. A packaged optoelectronic device according to claim 14,wherein the conductive adhesive material is an anisotropic conductivefilm.
 18. A packaged optoelectronic device according to claim 14,wherein the conductive adhesive material is an isotropic conductivefilm.
 19. A packaged optoelectronic device according to claim 14,wherein the conductive adhesive material is a conductive silver filledepoxy.
 20. A packaged optoelectronic device according to claim 14,wherein the plurality of conductive patches is sandwiched between thefirst barrier layer and a second barrier layer.